Pterosaurs were an ancient group of winged reptiles that lived alongside the dinosaurs. Many pterosaurs were very large, some as large as a giraffe and with a wingspan of over 12 meters. Paleontologists have long wondered whether large pterosaurs were capable of powered flight (flying by flapping their wings) or whether they were able only to glide. Several arguments have been made against powered flight.
Doubters point out that since modern reptiles are cold-blooded, ancient reptiles such as pterosaurs were probably cold-blooded as well. Cold-blooded animals typically have a slow metabolism and are unable to produce a lot of energy. Powered flight is an activity requiring a lot of energy, which is why all modern vertebrates that fly are warm-blooded, not cold-blooded. It seemed unlikely that pterosaurs would have been able to generate the energy needed to fly.
Second, there is a limit to the weight of animals that can be kept airborne by powered flight. Pterosaurs that were as large as a giraffe were probably so heavy that they would not have been able to flap their wings fast enough to stay aloft for any length of time.
Third, all animals with powered flight are able to take off from the ground. For example, birds take off by jumping from their legs or running to gain speed and then jumping. But these methods would not have worked for large pterosaurs. Large pterosaurs would have needed big, powerful muscles in their back legs to launch themselves into the air, and we know from fossilized bones that their back leg muscles were too small and weak to allow the pterosaurs to run fast enough or jump high enough to launch themselves into the air.
The reading passage and the lecture both discuss whether or not pterosaurs were capable of powered flight. The author of the article argues that these animals did not have the ability of powered flight due to three main reasons. However, the lecturer casts doubt on the claims made in the excerpt. She, instead, elaborates that the possibility that those ancient reptiles had the necessary traits for powered flight is still plausible.
First of all, the writer contends that pterosaurs, as reptiles, would not have been able to generate enough energy for powered flight because they probably were cold-blooded animals with slow metabolism like modern reptiles. The speaker, on the other hand, brings the fact that pterosaurs had dense hair or fur covering which is a unique characteristic for warm-blooded animals. She further explains that this thick layer kept their internal body temperature high enough when the external temperature drastically dropped.
Secondly, the author posits that Pterosaurs were too heavy to to be able to move their wings fast enough to fly or even to stay aloft for any given length of time. Conversely, the lecturer asserts that Pterosaurs had anatomical features that enabled them to fly. She indicates that Pterosaurs' bones were hollow, which allowed them to have a light weight despite their large body frame.
Lastly, the author holds that evidence from the fossilized bones showed that the pterosaurs' muscles in the back legs were small and weak, which would not have empowered them to launch themselves into the air by jumping or running then jumping like birds. Nevertheless, the professor points out that Pterosaurs might have used all four limbs similar to modern bats, which is enough to push them off the ground.
| Post date | Users | Rates | Link to Content |
|---|---|---|---|
| 2019-12-06 | marii.r67 | 80 | view |
| 2019-11-13 | shirley5001 | 80 | view |
| 2019-11-13 | shirley5001 | 80 | view |
| 2019-11-03 | Seema Modak | 78 | view |
| 2019-11-03 | Seema Modak | 78 | view |
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Grammar and spelling errors:
Line 1, column 50, Rule ID: WHETHER[7]
Message: Perhaps you can shorten this phrase to just 'whether'. It is correct though if you mean 'regardless of whether'.
Suggestion: whether
...ng passage and the lecture both discuss whether or not pterosaurs were capable of powered flig...
^^^^^^^^^^^^^^
Line 9, column 60, Rule ID: ENGLISH_WORD_REPEAT_RULE
Message: Possible typo: you repeated a word
Suggestion: to
...r posits that Pterosaurs were too heavy to to be able to move their wings fast enough...
^^^^^
Line 9, column 342, Rule ID: LIGHT_WEIGHT[1]
Message: Did you mean 'lightweight'?
Suggestion: lightweight
...re hollow, which allowed them to have a light weight despite their large body frame. L...
^^^^^^^^^^^^
Transition Words or Phrases used:
conversely, first, however, lastly, nevertheless, second, secondly, so, still, then, first of all, on the other hand
Attributes: Values AverageValues Percentages(Values/AverageValues)% => Comments
Performance on Part of Speech:
To be verbs : 10.0 10.4613686534 96% => OK
Auxiliary verbs: 3.0 5.04856512141 59% => OK
Conjunction : 6.0 7.30242825607 82% => OK
Relative clauses : 18.0 12.0772626932 149% => OK
Pronoun: 27.0 22.412803532 120% => Less pronouns wanted
Preposition: 30.0 30.3222958057 99% => OK
Nominalization: 1.0 5.01324503311 20% => More nominalizations (nouns with a suffix like: tion ment ence ance) wanted.
Performance on vocabulary words:
No of characters: 1490.0 1373.03311258 109% => OK
No of words: 285.0 270.72406181 105% => OK
Chars per words: 5.22807017544 5.08290768461 103% => OK
Fourth root words length: 4.10876417139 4.04702891845 102% => OK
Word Length SD: 2.49575570775 2.5805825403 97% => OK
Unique words: 175.0 145.348785872 120% => OK
Unique words percentage: 0.614035087719 0.540411800872 114% => OK
syllable_count: 444.6 419.366225166 106% => OK
avg_syllables_per_word: 1.6 1.55342163355 103% => OK
A sentence (or a clause, phrase) starts by:
Pronoun: 2.0 3.25607064018 61% => OK
Article: 9.0 8.23620309051 109% => OK
Subordination: 1.0 1.25165562914 80% => OK
Conjunction: 0.0 1.51434878587 0% => OK
Preposition: 1.0 2.5761589404 39% => More preposition wanted as sentence beginning.
Performance on sentences:
How many sentences: 12.0 13.0662251656 92% => OK
Sentence length: 23.0 21.2450331126 108% => OK
Sentence length SD: 49.5207588346 49.2860985944 100% => OK
Chars per sentence: 124.166666667 110.228320801 113% => OK
Words per sentence: 23.75 21.698381199 109% => OK
Discourse Markers: 9.66666666667 7.06452816374 137% => OK
Paragraphs: 4.0 4.09492273731 98% => OK
Language errors: 3.0 4.19205298013 72% => OK
Sentences with positive sentiment : 2.0 4.33554083885 46% => More positive sentences wanted.
Sentences with negative sentiment : 4.0 4.45695364238 90% => OK
Sentences with neutral sentiment: 6.0 4.27373068433 140% => OK
What are sentences with positive/Negative/neutral sentiment?
Coherence and Cohesion:
Essay topic to essay body coherence: 0.223268393253 0.272083759551 82% => OK
Sentence topic coherence: 0.0800690954885 0.0996497079465 80% => OK
Sentence topic coherence SD: 0.0631160732883 0.0662205650399 95% => OK
Paragraph topic coherence: 0.13454948848 0.162205337803 83% => OK
Paragraph topic coherence SD: 0.0540624798225 0.0443174109184 122% => OK
Essay readability:
automated_readability_index: 15.1 13.3589403974 113% => OK
flesch_reading_ease: 48.13 53.8541721854 89% => OK
smog_index: 8.8 5.55761589404 158% => OK
flesch_kincaid_grade: 12.3 11.0289183223 112% => OK
coleman_liau_index: 13.35 12.2367328918 109% => OK
dale_chall_readability_score: 8.66 8.42419426049 103% => OK
difficult_words: 70.0 63.6247240618 110% => OK
linsear_write_formula: 11.0 10.7273730684 103% => OK
gunning_fog: 11.2 10.498013245 107% => OK
text_standard: 11.0 11.2008830022 98% => OK
What are above readability scores?
---------------------
Rates: 90.0 out of 100
Scores by essay e-grader: 27.0 Out of 30
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Note: the e-grader does NOT examine the meaning of words and ideas. VIP users will receive further evaluations by advanced module of e-grader and human graders.